package com.taca.common.util;

import java.security.MessageDigest;

public class MD5Util {
   
		 // MD5加码。32位    
		 public static String MD5(String inStr) {    
		  MessageDigest md5 = null;    
		  try {    
		   md5 = MessageDigest.getInstance("MD5");    
		  } catch (Exception e) {    
		   System.out.println(e.toString());    
		   e.printStackTrace();    
		   return "";    
		  }    
		  char[] charArray = inStr.toCharArray();    
		  byte[] byteArray = new byte[charArray.length];    
		    
		  for (int i = 0; i < charArray.length; i++)    
		   byteArray[i] = (byte) charArray[i];    
		    
		  byte[] md5Bytes = md5.digest(byteArray);    
		    
		  StringBuffer hexValue = new StringBuffer();    
		    
		  for (int i = 0; i < md5Bytes.length; i++) {    
		   int val = ((int) md5Bytes[i]) & 0xff;    
		   if (val < 16)    
		    hexValue.append("0");    
		   hexValue.append(Integer.toHexString(val));    
		  }    
		    
		  return hexValue.toString();    
		 }    
		    
		 // 可逆的加密算法    
		 public static String KL(String inStr) {    
		  // String s = new String(inStr);    
		  char[] a = inStr.toCharArray();    
		  for (int i = 0; i < a.length; i++) {    
		   a[i] = (char) (a[i] ^ 't');    
		  }    
		  String s = new String(a);    
		  return s;    
		 }    
		    
		 // 加密后解密    
		 public static String JM(String inStr) {    
		  char[] a = inStr.toCharArray();    
		  for (int i = 0; i < a.length; i++) {    
		   a[i] = (char) (a[i] ^ 't');    
		  }    
		  String k = new String(a);    
		  return k;    
		 }    
		     
		 // 测试主函数    
		 public static void main(String args[]) {    
		  String s = new String("a");    
		  System.out.println("原始：" + s);    
		  System.out.println("MD5后：" + MD5(s));  
		  System.out.println("MD5后：" + MD5(s)); 
		  System.out.println("MD5后再加密：" + KL(MD5(s)));    
		  System.out.println("解密为MD5后的：" + JM(KL(MD5(s))));  
		  System.out.println(JM(MD5(s)));
		 }    
		    

}
